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roche314
09-07-2007, 01:29 PM
The car has been sitting for about a year with no motor.
I put the motor back in yesterday (has 500 miles on it with new cam).

While breaking in the cam the car started to get :flame: hot ~240 before I shut it down. There were no air pockets in the system, and I could feel pressure in the top radiator hose, so I assume the thermostat opened. The motor has a brand new water pump, and the radiator is was about a year old before the car sat. I let the temp cool down to about 200 and fired it back up, this time I noticed that the electric fan never went on. The temp started to climb again so I shut it down. (probably got about 20 minutes total on the motor).
Would the temp climb that high just because the fan wasn't on?
What is the best way to trouble shoot the fan?


thanks
-steve

PaCemkr86
09-07-2007, 01:37 PM
yes.. without at fan, they will get hot..
is your ect sensor plugged in ?
double check your fan relays,

PaCemkr86
09-07-2007, 01:38 PM
also by turning the a/c on, should turn the fans on HIGH speed.. this will also be a quick test, to see if the fan motor works etc..

Keller
09-07-2007, 05:37 PM
There is also a tab in the ALDL connector you can ground to get the fan to start.

roche314
09-18-2007, 02:39 AM
If i understand everything correctly, the ecm will turn on the low speed fan and the switch located by the fuel pressure regulator on the top of the intake manifold will turn on the high speed fan by ground out the relay. I tested the relay by manually grounding out this wire, and the fan comes on.

Questions:
1. When does the computer turn on the low speed fan?
2. What temperature does the switch for the high speed fan close?

thanks.

Keller
09-18-2007, 02:20 PM
1. When does the computer turn on the low speed fan?
2. What temperature does the switch for the high speed fan close?

1. At whatever temp the chipmaker put in for it to come on. Many aftermarket chips have it come on at 160F. The stock chip was set to 190F, I believe.
2. Not sure, but I think the switch kicks at like 200-210F.

The A/C will only turn it on under MAX. You can unplug the compressor to run the engine fan and not run the A/C.

PaCemkr86
09-18-2007, 03:42 PM
im pretty sure the cooling fan comes on anytime the a/c is turned on

PaCemkr86
09-24-2007, 09:35 AM
any updates on this running hot issue ?

roche314
09-24-2007, 11:55 AM
Phil, here is my update, sorry I haven't updated this lately, but I have been getting my circle track car ready.

* the high speed fan switch works (the one located under the fuel pressure regulator) I'm not sure what temp it turns on at, but I pulled it out and tested it with a torch and a continuity tester.

* I was getting my temp reading from an aftermarket temp gauge(w/electric sending unit), but I connected my laptop to the car and the temperatures did not match. The ecm was saying around 180-190, while the gauge climbed up to 250. So I temporarily wired up a different gauge (straight off the battery) and ran the car again, this time the ecm and the gauge matched dead on, the car never got over 200.

* Then I noticed some strange behavior. If I turned the headlights on, the old gauge went to 250 degrees, and the oil pressure gauge went to 0. Sounded like a grounding issue, but I double checked all the grounds connected to the block and they all were ok.

* There is a bunch of messy wiring under the dash. (keyless entry/alarm, stereo, gauges, etc) Some stuff the previous owner did and some my doing. I am going to remove the keyless entry/alarm, and clean everything up.

If anyone has any trouble shooting advice I would appreciate it.

thanks,
steve

PaCemkr86
09-24-2007, 05:20 PM
check the grounds on the drivers side kick panel